Engraving machine



Aug. 24, 1943. D, s. 'MCRAE 2,327,811

ENGRAVING MACHINE Filed April 1, 1942 2 Sheets-Sheet 1 Dan/e/ 5. Mc/Qae INVENTOR m 1/2 BY w ATTORNEYS Aug. 24, 1943. D, B, MCRAE 2,327,811

ENGRAVING MACHINE Fild April 1, 1942 2 Sheets-Sheet 2 Dan/ e/ 5. Mc/Pae INVENTOR ATTORNEYS Patented Aug. 24, 1943 Eastman "Kodak: Company, Rochester, corporation of New- Jersey N, Y a

asst-wash April 1, 1942, Sei-ial'No. 438301 8 claims. (01. ts-23) This invention relates to 'engfeviii' "machines and more particularly t a means for controlling the engraving tool. One object off'r'ny" invention is to provide a mechanism for raisingfand lowering an engraving tool withvrespct tothe'vvork to be engraved. Anothr'object off'my. invention is to provide aimecnamsm 'Whih will raise and lower the engravingtbolinslich'a manner'that only the desired pattern wilfappe ar (mfthe work. 7

Another object of my iriventioh'is to 'provide'a means for controlling the 'f'enfg rigfto'cl which will greatly reduce or; ntirely el minate vibration of the tool particular finfmbvingintor contact with and in movingaway'fifom wqrk. "Still another object" 'of my invention is to provide an engravingtool capable of producing extremelyfin'e work, particularly when'usedfor removinga wax coating rrom'work to 'lfie ngravefi. l

In a g'o'odmany engraving oner'aitions itis customary to provide some, ionn qr paragra arrangementby whichfiriove'inri't of aist'ylus en'a relatively large scale will be transmitted to movement for an engravingftoolion' a relatively small scale. It is usually necessary to lift'the' engraving tool from the work and tom'ov'e th engravin tb'ql into contact with the workfquite'a'numbe'r of times in engraving asiriglepi'ece, thenumbr of that in raisingor loweringthe ehgravirig'tool a slight vibration may OCCuifl Whih; win ,pi o'duce undesirable line'son the 'work. Ih is'is particu: larly apt to occur where'the'engraving is Dre uceg by, fir Cutting a vain-lamina in'wa 'cb titis and then etching thisfpattrnfwith a suitable etching fluid to reproducefa' p'atter'n on'the work. It is to overcome these di'flicultis fthiil; I have designed my particiilar 'Ihethodbf controlling an engraving tool. v g v M Corning now to the drawings wherein like refer erice characters denote like partsthroughout:

Fig. 1 is a persr ecti've view'showing abortion of an engraving machine which'include s'a preferred embodiment of my mechanism for controlling an engraving tool M I Fig. 2 is a schematic view showing partially in section portions of my-engr-aving tool controlling mechanism; V

Fig. 3 is a schematic showing of 'apantograbh whichmaybeuse'd' on an engraving 'machine employing my engraving tooIE'controHi'ri'g mechanism;

pattern engraved thereon;

Fig. 4-is an enlargetl viewer w rk having-a :F'igf5 is a'i'side elevation through work brep'ared for engraving fi' -v isefdi e i l s r n my mme method of raising and loweringfthe engraving 6001; v t v -*'7 is"an eri larged fraginentary detail shew a ing the results of vibration which may occur in raising or lowriri g' an engraving tool; and

"Fig. 8 is a view similar to Fig. 7 but shbvv-ingthe resultobtained by eliminating vibration of the n en ere .i t a 1 "Sinceiriy' in "t'io'n is pairticularl'y adapted for producing engravings or' f ne lines'io'nfa surface such as glass by first 1 cutting 3 through a thinlwax U on the g ia'ssandiater'tching the lines so cu with asuita'ble ietching-iluijdgsuchj as hydrofiuoric acidigas, Ifwilll'describ'e fsi' ch an engraving machine, it being understood that this f is by Way of illustration omy, since: mprove mechanism can ob'vioulsl'i *he used with any type "of enl n 5 li j (.f 'a t fWh h t wbrkpiecjsi ma he-molint d and'rnay bep'osi- ,tioired b means er'tiiesetstie ssagia the spri g arms' a which arranged to hol'd thewerkpieces hacliingf ii g v Idisc l to hold a'e ahd 'athin wax coating Qjrhay be placed ove the surface' to be "engraved. Theenfgraving tool in this'inst'a'n'ce may be a to scratch through the wax coatingtleaving an open channel through"which'theftching fluid sim orta large answerer theworkpie'ces 2,"s':u'(;h as "25' or 50 pieces, 'biit sin'e "all of the engraving "6615, are duplicates, onl a email section of a 'machine will illustrated in "the 'drawiiigs.

The' glass disc '1 mayte'eroviaeu with'any pan terna-wpica crie'being shoWn'in'Fig. 4 in which cross-hairs 'e'xt'endover the center of the gla'ss disc I and these cross-Hairs are numbered, the one nmiiin'g from rightjt'o left with regard to Fig. 4 being number 'I, *2, and the cross-Hair running at right angles th'ereto being number 354. Inordr'to give someidea of'the tyh 'an'd *iili'a y bf wdikdvhih bln be a ccbmpli sh d with my machine, I might point out that the crosshairs may be substantially .0005 in Width and that the numerals may be substantially .0025 in height, this being substantially the dimensions of workpieces which have been turned out in large numbers. Of course it is possible to make much wider lines very easily and it is also possible to make still finer lines, although this is considerably more difficult. It is to. be understood that these dimensions are merely to give a general picture of work that can be accomplished and do not indicate the minimum'width of line that can be produced with the tool which will now be dey scribed. I As will be obvious, an engraving tool capable making a fine line as indicated above is extremely delicate and the point of said tool can be easily marred by treatment which would not ordinarily be considered rough through bringing the point too rapidly into contact with the surface to be ;engraved.- It is, therefore, necessary to use extreme care in moving the tool toward the work so that the point will contact very gently with the work to preserve itspoint-as long as possible. It might be pointed out that with some pieces of work it is necessary to raise and lower the engraving tools more than one hundred times, and it will thus be seen that it is very difficult to keep the fine pointed tools in proper shape, for the best work.

One of the advantages of permitting the engraving tools to be automatically brought into engraving contact with the'work by heating a wire is that, while this operation takes place fairly rapidly, since normally ithe engraving tools are spaced from the work in-the neighbore hood of .02", the speed of movement is nevertheless insufficient to permit the engraving tools to strike the work wi-th suflicient force to man the points of the tools. This is an extremelyimportant feature of my invention. i

In causing the tool II] to produce the desired pattern in the wax coating 9, it is'desirable to press the tool It] into contact with work with a predetermined pressure. This is accomplished by providing arigid toolholder in the form of a framework I2 having at the outer end a block I3 through which the engraving tool I0 passes and,

in which the engraving tool is held in'the desired position by means of a setscrew I 4.

' The rigid frame member I2 may be connected to a spring member I5 which is here shown as a'thin spring metalplate having a downwardly curled edge I6 and fastened by means of screws I1 and I8 to aframe member I 9, ,The screws I8 also, support brackets .20 carrying the uprights 2| which are apertured at-22 to form bearingsforarod23.

The spring member I 5 is provided with a screw 24 and a nut 25 which extend through the spring member I5 and into a bracket 26 carriedby the frame member IS. The purpose of this screw is to vary the tension on the spring member I5 and it is normally used in setting up the machine for any desired type of work. Spring I5 exerts a downward thrust upon the frame member. I2 and block I3, thus'tending to press the engraving tool I0 toward the workpiece 2 with a predetermined force. Thus, the spring I5 can be adjustedto apply just the required downward pressure to the engraving tool II! to make a clean cut II through the wax coating 9.

It is of course necessary -to-raise and lower the engraving tool It toward the workpiece l, and it is in this raising and lowering'thatdifficulties 'plish the desired result;

frequently occur. Referring to Figs. 7 and 8 showing fragmentary views of cuts II in a Wax coating 8, it will be noticed from Fig. 7 that the groove II cut in the wax coating has a curved tail or end at III. Such an undesirable mark is quickly produced if there is any vibration in the engraving tool as it is raised from or as it is lowered to the work. On the other hand, in

Fig. 8,,thee'nd I I2 of the groove II is smooth and r' invention, because where extremely fine lines are provided the imperfections while noticeable do not show up as clearly as in Fig. 7.

In orderto raise and lower the engraving tool may be attached to the frame vI2,or to the block I3 in any suitable means'as by a screw 28. The upper end of the wire 21 may be wrapped around the cylindrical portion 29 of the member 30 on the rod 23 andsecured by the set screw,3I. The member 36 is provided with a knurled flange 32 tofacilitate turning the member 30 on therod 23 to adjust the tension on wire 21 and so that, after this tension is adjusted to the required degree, the setscrew 33 may be turned to secure the member 30 on the rod 23. v

In setting up the machine, the wire 21 is permittedto remain slack while the ,setscrews and nutsv 24, 25 are adjustedso that the spring I5 will exert-therequired downward pressure upon the engraving'tool'j It When this,is1 -l done,.-, the knurled member 32, is turneduntilthe engraving tool Ill is raised from the work approximately a millimeter at which time the setscrew 33 is tightenedto hold the parts in the position shown in'Fig'. 2., Thus,'the wire 2! opposes the spring I5 andI prefer to'select the wire 21 of a material "whichisparticularly susceptible to, changes in temperature, and'thesetting' up of the, machine as indicated in Fig. 2 should take place with the (parts at room temperature. Inv the present em bodiment of my inven'tion I use a No. 36 Manganinwirev because this is 'quite suitable army purpose. Referring to Fig. 6, if the wire 21fis 6" long from U to W, and if the distance to if is approximately 4 using the vNo. 36 Manganiri wire and applying to it a current ,of'.0.5to 0.9ianipere, the point U could vbe raised orlowered approximately amillimeter 'so that theqdistance D would be, suflicientto raise the engraving tool ,I 0 from the workfor, .to lower it .toward 'thwork according to whether .or not the wire 2'! isj'hea'ted electrically With the current-described. Here; again, the figures are by-way of illustration only, because by varying the 'size or kind of'wire or by varying the length of the wire and other proportions, itmaybe necessary to use considerably more or less current toaccom- I prefer, however, to heat the wire 21 electrically because this has-a very desirable result in that as the wire 21 is heated, the engraving tool descends at a reasonable speed and not at a speed sufiicient to cause any vibration. Thus, when the wire is-heated it expands and permits the leaf spring I5 toipress the 'engravingtool toward the work with the desired pressure, since the Wire 21- becomes slack and does not Opp se the movement of the spring lFi. As soon as;

aea'asr i 'is desirable-to iaise" tii eiigravmg teei' i ngtne *wires" 40,?41. From this source a wire j'z leads to the spring [5 through-a connectirrgwire fi which is insulated on 'a 'bl'ock -fl from' the frame member [9. -A- second wire 45 leadsto a switch '46 from which awire 4'lleads to a"'shaft23.

Thus, when 'the s'witch 46 is #closetia" circuit is -mad'e heating the wire?! and-causing it 'to' ex the switch-the wire '2"! may 0661: Asindicated in r'i 3, I findit convenientto make the switch 45 r a roet-operates switch ane place it in front of a; Chair 49 in whi'ch antiperator sitsi'n operating the engraving 'machine. This view shows-"a panto'graph consisting-d {a series of pivoted sectionsfill wlrich arefconn "te'd paid, and vvh'enaspringWB is permittedtoo'pn "by the bars'Sl to pivotedbaifs 2 w o-f the'b'ars 51 being-pivotally mounted a S -to the frame. The bars 52 are attached by 'l'inks S' l to-the mavable frame member ls which"carries thesprings l5 so that thisineniber moves when a stylus 55 is moved by an operator sitting in the chair 49, the stylus being moved through the grooves 56 forming the pattern to be engraved, these grooves being cut in a master plate 51. The pattern on plate 51 is preferably enlarged a great many times so that the pantograph may reduce the movement of the engraving tool ID to that required for the particular work in hand.

This pantograph forms no part in my present invention and has only been generally described to indicate how a preferred embodiment of my invention may be applied to a known type of engraving machine.

In operation the machine is extremely simple. Assuming that work is to be engraved as indicated in Fig. 4, the glass disc I may be placed in the frame 5 andmay be coated on the back with a thick coating 8 of wax and on the top surface with a thin coating 9 of wax in which the pattern is to be engraved. The workpiece thus prepared is placed on the table I and is positioned by the screws 3 and springs 4. As above explained, it is customary to simultaneously provide a large number of these'workpieces. With the parts thus positioned, and with the engraving tool in the position shown in Fi 2, an sperator sitting in the chair =49 moves the stylus 55 into engagement with the end of a slot near the numeral 3. 46 so that the wire 2'! will be heated and asv it becomes heated the engraving tool. I!) will move smoothly down into an engraving. position, The operator then moves the stylus down the slot toward 4 and the needle ID moves a proportionate distance through the Wax 9 leaving a groove ll.

At the end of this stroke the operator releases l the switch ie and the spring 48 breaks the circuit causing the wire 21 to cool. In cooling, the engraving tool rises from the wax without vibration. This smooth upward and downward movement of the engraving tool definitely prevents by the manual eperatrons 3 except of course i for "a 7 e lin'e's'thr thew-ax during that p rt-i of tlieltiinetha is pressed'ag'ainstthe we kbymeanserthe s rin'g 1'5. v a

" ne'g ardless of the number bf ='engraving"tools which are -us"cd simultaneously, the action of all i of tli'em inlalisii'fg' or lowering fror n work can' be "'iidll'y' contrelied -by"th'e 'electiicai l'ieating cir- 'cuit illustrate'din Fig. 2.: Obviously'otherbir- =cuits might be made and the *Wire 21 -heate'd in -any desired mannerbut rnn'd that, by permitting the *wirefi'l I to be Eheated' and cooled: "extremely smooth and even inovement of-ithe engra'ving tool to anwrrom the-work: ean be obtained. 1.

I claims J 1. An engraving machine, including,in combination, 1 atable'bn which work'to be engraved nia'y b'e placd, an'engravingtool mounted over He then depresses the foot switch the table, a mount 'fo'r theengraving tool compricin *3.- spring arm tending to thrust the eng'raving tdol to'wardworkcarried by the table and a heatable member supporting said-spring arm "and opposing saids ring movement, and means ier heating said heatablemernber' wherespring arm may move the engraving tool into' c'oi act with work. 2*

2. "An ':'ezigraving 1 machine, includi ng, in oombiriation, a E table on which -'work "to be engraved may be placed, an engraving toohmountedover the table, a mount for the engraving tool comprising a spring arm tending to thrust the engraving tool toward Work carried by the table and a wire connected to the spring arm and normally holding said engraving tool out of contact with work when said wire is of substantially room temperature, means for raising the temperature of said wire to above room temperature whereby expansion of said wire may permit the spring arm to press the engraving tool into contact with work,

3. An engraving machine, including, in combination, a table on which work to be engraved may be placed, an engraving tool mounted over the table, a mount for the engraving tool comprising a spring arm tending to thrust the engravingv tool toward work carried by the table, and a wire connected to the spring arm and normally holding said engraving tool out of contact with work when said wire is of substantially room temperature, an electric circuit including said wire, a. switch for controlling said circuit, whereby a heating current may be passed through said wire to heat and expand the wire and whereby the spring arm may contact the engraving tool and work. 1

4. An engraving machine, including, in combination, a table on which work to be engraved may be placed, an engraving tool mounted over the table, a mount for the engraving tool comprising a spring arm tending to thrust the engraving tool toward work carried by the table and a wire connected to the spring arm and normally holdwhen saidwire is of substantially room temperature, an electric circuit including said wire, a

switch for controlling said circuit, said circuit and wire being so selected that upon closing the switch the wire may be heated well above room temperature whereby the wire may expand a distance sufiicient to remain slack while so heated and while the engraving tool is pressed into contact with said work by the spring arm, and, when the switch is opened, the wire may contract raising the engraving tool from the work a said wire cools to room temperature,

5. A toollcontrolafor engraving machines including, in combination, a work table adapted to'carry work to be engraved, asupport, a spring actuated arm carriedby the support and tending to move toward the work table, an engraving tool carried by jthespring arm and located over work ,on'the table, a wire connecting the spring arm and support of a type affected by changes in temperature, the wire at room temperature holding the engraving tool above the work, means for heating the wire until the spring arm may control the pressure on the engraving tool against work positioned on the work table," and an adjusting screw acting on the, spring arm for predetermining the pressure on the engraving tool by said spring.

6. A tool control for engraving machines including, in combination, a work table adapted to carry work to be engraved, a support, aspring actuated arm carried by the support and tending to move toward the work table an engraving tool carried by the spring arm and located over work on the table, a wire connecting the spring arm and support of a type affected by changes in temperature, the wire at room temperature holding the engraving tool above the work, and manually controlled electrical means for increasing the temperature of the wire to control its supporting effect on the spring arm. I

7. A tool control for engraving machines, the

combination with a table adapted to support work to be engraved, of an engraving tool, a support for the engraving tool comprising a rigid member adjustably carrying the engraving tool, a flat spring connected to the rigid member tending to move the engraving tool in one direction, a frame carrying said'spring, an adjusting screw for" varying th relation of vthe flat spring and frame to vary thespring tension thereof, a wire connected to the rigid member carrying the engraving tool and of a type adapted to alter in length through variations in temperature, said wire normally resisting the tendency of the spring to move the engraving tool in one direction, and means for changing the temperature of said wire at the-will of an operator. DANIEL B. McRAE. 

